enable messages for iCloud
hi, I've trying to enable messages for iCloud on my Mac, I've download the new iOS 11.4 on iPhone/ipad and messages for iCloud is activated on both, an new iTunes version was released and installed that. but doesn't seem to be a macOS update released, so don't know how to activate this. or am I missing something?
thanks in advance
iMac (Retina 5K, 27-inch, Late 2014), macOS Sierra (10.12.6)